Alunogen Mineral Data

General Alunogen Information

Chemical Formula:

Al2(SO4)3•17(H2O)

Composition:

Molecular Weight = 648.41 gm

Aluminum 8.32 % Al 15.72 % Al₂O₃

Hydrogen 5.29 % H 47.23 % H₂O

Sulfur 14.84 % S 37.04 % SO₃

Oxygen 71.56 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al₂(SO₄)₃•17(H₂O)

Environment:

Secondary mineral commonly associated with coals and pyritiferous shales in arid regions.

IMA Status:

Valid Species (Pre-IMA) 1832

Locality:

Alum Mountain district, Grant County, New Mexico, USA. Link to MinDat.org Location Data.

Name Origin:

From the Latin alumen ="alum" and the Greek genos ="origin."

Name Pronunciation:

Alunogen

Synonym:

Aluminum Sulfate

Doughtyite

ICSD 4292

Keramohalite

PDF 26-1010

Alunogen Image

Images:

Alunogen Jarosite

Comments: Colorless to white, tabular crystals alunogen on reddish jarosite.
Location: Ronneburg U deposit, Gera district, Thuringia, Germany. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Images:

Metavoltine Alunogen

Comments: Yellow metavoltine with white alunogen.
Location: Carola Mine, Freital, near Dresden, Saxony, Germany. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Images:

Voltaite Alunogen

Comments: Dark greenish-black crystals of voltaite on white alunogen.
Location: Carola Mine, Freital, Dresden, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Alunogen Crystallography

Axial Ratios:

a:b:c =0.2751:1:0.2247

Cell Dimensions:

a = 7.42, b = 26.97, c = 6.062, Z = 2; alpha = 89.95°, beta = 97.566°, gamma = 91.888° V = 1,201.90 Den(Calc)= 1.79

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 4.49(1), 4.33(0.8), 4.39(0.8),13.5(0.6), 3.68(0.5), 3.9(0.5), 3.02(0.4),

Forms:

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Forms: ( 0 1 0) ( 1 4 0) ( 1 1 0) ( 1 1 1) ( 1 0 0)

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Physical Properties of Alunogen

Cleavage:

{010} Perfect, {100} Very Good, {313} Distinct

Color:

White, Yellowish white, Reddish white, Yellowish white.

Density:

1.65 - 1.78, Average = 1.71

Diaphaneity:

Transparent

Fracture:

Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

1.5-2 - Talc-Gypsum

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Alunogen

Gladstone-Dale:

CI meas= -0.072 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.027 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2657,KPDmeas= 0.2774,KC= 0.2587
Ncalc = 1.43 - 1.46

Optical Data:

Biaxial (+), a=1.473, b=1.474, g=1.48, bire=0.0070, 2V(Calc)=46, 2V(Meas)=31-69. Dispersion none.

Calculated Properties of Alunogen

Electron Density:

Bulk Density (Electron Density)=1.88 gm/cc
note: Specific Gravity of Alunogen =1.79 gm/cc.

Fermion Index:

Fermion Index = 0.0014640919
Boson Index = 0.9985359081

Photoelectric:

PE_Alunogen= 1.26 barns/electron
U=PE_Alunogen x rElectron Density= 2.37 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Alunogen is Not Radioactive

Alunogen Classification

Dana Class:

29.08.06.01 (29)Hydrated Acid and Sulfates

(29.08)where (A)2 (XO4)3 � x(H2O)

(29.08.06)Dana Group

29.08.06.01 Alunogen Al2(SO4)3•17(H2O) P1 1

Strunz Class:

07.CB.45 07 - SULFATES (SELENATES, TELLURATES)

07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O

07.CB -With only medium-sized cations

07.CB.45 Alunogen Al2(SO4)3•17(H2O) P1 1

07.CB.45 Meta-alunogen Al4(SO4)6•27(H2O) Mono

Other Alunogen Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Alunogen :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

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Alunogen

Al2(SO4)3•17(H2O)
Dana No: 29.08.06.01 Strunz No: 07.CB.45
Locality:

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